I always care about my monthy paymets (for the internet, rent, insurance etc.) but I don't have and overview of these payments. I keep it in Excel document.

But I tried to design simple app for this! You can just make a rows for each payment and when it's paid just tick it, like in some to-do app. You can watch amounts of money, last day to pay, already paid things and you have easy access your PayPal or bank account.